Is there a particular reason for using conjugate heat transfer for this simulation? I would normally expect either incompressible (if temperature/buoyancy effects are not of your interest) or convective heat transfer for such simulations.
On the question about the nostrils: it depends on the time dependency that you are looking to use. If it’s a transient simulation, I commonly see the velocity being defined via a table.
I would strongly suggest that you start off with a simple steady-state simulation though, to get a feeling for the setup. Transient studies require extra caution (this webinar is insightful).
PS: you should be able to find similar projects in the public projects section.